Drinking soft drinks is associated with higher blood pressure, according to a study of over 2,500 people reported this week in the journal Hypertension. High blood pressure is a major risk factor for heart disease, which is the leading cause of death worldwide. Someone with a blood pressure level in millimetres of mercury (mmHg) of 135 over 85 is twice as likely to have a heart attack or stroke as someone with a reading of 115 over 75.

The new research shows that for every extra can of soft drink consumed per day, participants on average had a higher systolic blood pressure by 1.6 mmHg and a higher diastolic blood pressure by 0.8 mmHg. This difference was statistically significant even after adjusting for factors such as weight and height. The study did not examine the mechanism that might link soft drinks with blood pressure. However, the researchers suggest that raised uric acid, which has been linked to soft drink consumption, might raise blood pressure by reducing the levels of nitric oxide, a chemical that relaxes the lining of the blood vessels.

The association between soft drinks and higher blood pressure was especially strong in people who consumed a lot of salt as well as sugar. Diet drinks were linked with lower blood pressure levels in some analyses, but the association was not consistent or strong. Professor Paul Elliott, senior author of the study, from the School of Public Health at Imperial College London, said: “It’s widely known that if you have too much salt in your diet, you’re more likely to develop high blood pressure. The results of this study suggest that people should be careful about how much sugar they consume as well.”

The researchers analysed data from 2,696 volunteers aged between 40 and 59, in eight areas of the US and two areas of the UK. On four separate occasions over a period of three weeks on average, the participants reported what they had eaten in the preceding 24 hours, as well as giving urine samples and having their blood pressure measured. The volunteers were taking part in INTERMAP, the International Study of Macronutrients, Micronutrients and Blood Pressure.

The researchers also found that people who drink more soft drinks tended to have more unhealthy diets in general. As well as consuming more sugar, those consuming more than one soft drink a day consumed more calories by 397 kilocalories per day on average, and less fibre and minerals. Those who did not consume soft drinks had a lower body mass index (BMI) on average than those who consumed more than one drink per day. “Individuals who drink a lot of sugar-sweetened beverages appear to have less healthy diets,” said Dr Ian Brown, the study’s first author, also from the School of Public Health at Imperial College London. “They are consuming empty calories without the nutritional benefits of real food. They consume less potassium, magnesium and calcium.” “This is a population study,” Dr Brown added. “It can’t say definitively that sugary drinks raise your blood pressure, but it’s one piece of the evidence in a jigsaw puzzle that needs to be completed. In the meantime, we would advise people who want to drink sugar-sweetened beverages should do so only in moderation.”

Eating a diet high in antioxidants may protect against ischemic stroke, an Italian cohort study showed.

People who had a diet high in total antioxidant capacity — an index that takes into account several different antioxidants and their interactions — had a 59% reduced relative risk of ischemic stroke (HR 0.41, 95% CI 0.23 to 0.74), according to Nicoletta Pellegrini, PhD, of the University of Parma in Italy, and colleagues. But there was no such relationship with hemorrhagic stroke, they reported in the January issue of the Journal of Nutrition. In fact, the highest intake of the antioxidant vitamin E was associated with a greater risk of hemorrhagic stroke (HR 2.94, 95% CI 1.13 to 7.62).

Considering evidence suggesting that oxidative stress and systemic inflammation are involved in the pathogenesis of ischemic stroke, the researchers noted that “a high-total antioxidant capacity diet could be protective as a consequence of its ability to deliver compounds with antioxidant activity and with a demonstrated anti-inflammatory effect.” But, they acknowledged that the mechanism for such activity was unclear may “go beyond the antioxidant activity of the numerous total antioxidant capacity contributors present in foods and beverages.”

Pellegrini and her colleagues set out to explore the relationship between dietary total antioxidant capacity and the risk of stroke among 41,620 people participating in EPICOR, the Italian segment of the European Prospective Investigation into Cancer and Nutrition (EPIC). None had a history of stroke or MI at baseline. Dietary intake was assessed with a food frequency questionnaire. In the study population, more than half of the total antioxidants consumed came from coffee, wine, and fruit. Through a mean follow-up of 7.9 years, there were 112 ischemic strokes, 48 hemorrhagic strokes, and 34 other types of strokes. After adjustment for energy intake, hypertension, smoking status, education, nonalcoholic energy intake at recruitment, alcohol intake, waist circumference, body mass index, and total physical activity, individuals eating a diet in the highest tertile of total antioxidant capacity had a reduced risk of ischemic — but not hemorrhagic — stroke.

Looking at individual antioxidants, the researchers found that participants consuming the highest amounts of vitamin C had a reduced risk of ischemic stroke (HR 0.58, 95% CI 0.34 to 0.99). Controlling for vitamin C intake did not negate the overall association between antioxidants and ischemic stroke, which ruled out the nutrient as the sole driver of the relationship. High intake of vitamin E, on the other hand, was associated with nearly triple the relative risk of hemorrhagic stroke. However, “it must be stressed that the small number of cases observed in this population strongly limits the validity of statistical observations on hemorrhagic stroke,” noted the researchers, who called for further studies.

Aside from anti-inflammatory effects, it is possible that the association between antioxidants and ischemic stroke risk can be explained by the interaction between polyphenols — the major contributors to total antioxidant capacity — and the generation of nitric oxide from the vascular endothelium. That interaction leads to the vasodilation and expression of genes that may be protective for the vascular system, according to the researchers. In addition, coffee — the main source of antioxidants in the study population — reduces blood pressure, which is a recognized risk factor for ischemic stroke, the researchers wrote.

They noted some limitations of the study, including the low numbers of cases when different types of stroke were analyzed, the measurement of total antioxidant capacity at baseline only, and the inability to rule out confounding effects of other dietary components, like sodium and potassium.

About one in seven Britons feels under extreme stress, a survey suggests.We can reasonably conclude that these numbers will be similar right here in Australia. Experts say stress raises blood pressure, putting people at greater risk of stroke. A poor diet and lack of exercise also contribute to the chances of suffering a stroke. Stroke is the third leading cause of death in the United States. Over 143,579 people die each year from stroke in the United States. Stroke is the leading cause of serious, long-term disability in the United States. Each year, about 795,000 people suffer a stroke. About 600,000 of these are first attacks, and 185,000 are recurrent attacks. Almost one in five women and one in 10 men feel their stress levels are out of control, according to the poll of 2,000 people in Britain.

The survey, by the Stroke Association and the engineering company Siemens, found almost a fifth of people said they took no exercise. A similar number said they exercised for 30 minutes once a week. More than a quarter of people aged 45 to 54 said they never exercised, despite suffering the highest stress levels. Almost half said they were under more than “moderate stress”. Overall, 40 per cent of those surveyed said they were unaware of the link between exercise and lowering the risk of stroke.

James Beeby, of the Stroke Association, said: “The research is incredibly worrying and emphasises the need for people to be aware of the dangers of stroke. “It’s imperative that people take regular exercise and modify their diet to reduce the risk of suffering a stroke.” Siemens sponsors the British rowing team and provides some funding for the Stroke Association’s Stroke for Stroke campaign. Andreas Goss, the chief executive of Siemens in the UK, said: “Contrary to popular belief, stroke can affect people of any age.”

The researchers analyzed data from the National Health and Nutrition Examination Survey (2003-2006) which consisted of 4,528 US adults 18 years of age or older that had no previous hypertension diagnosis. The survey asked about dietary habits and what foods and beverages that they consumed. The researchers said that those who ate 74 grams (about 2.5 cans of sugared soda) or more each day of fructose sugar, had shown an increased risk for developing hypertension. There was a 26 percent chance for these individuals to have high blood pressure reading at 135/85mmHg , a 30 percent higher risk to have high blood pressure measured at 140/90, and a 77 percent higher risk for having blood pressure measured at 160/100 mmHg. A normal blood pressure reading is under 120/80 mmHg.

The researchers point out that even though this shows a potential trigger for high blood pressure, a randomized clinical study would need to be conducted in order to prove that a low fructose diet would prevent hypertension.

Beetroot juice, a source of high nitrate levels, may help prevent high blood pressure, according to a study published in Hypertension. Nitrate is a compound that increases the amount of gas nitric oxide that circulates through the blood.In an effort to determine if beetroot juice contains enough nitrate to lower blood pressure, researchers had two groups of individuals either drink the juice or take nitrate capsules.

The results of the study showed that within 24 hours, the supplements and the juice had lowered the blood pressure of people in both groups. Furthermore, the investigators discovered that about 250 mL of beetroot juice was all that was needed to have the same effects on one's blood pressure as the nitrate capsules.

These findings showed that “beetroot and nitrate capsules are equally effective in lowering blood pressure, indicating that it is the nitrate content of beetroot juice that underlies its potential to reduce blood pressure,” said Amrita Ahluwalia, lead researcher of the study.

Metabolic syndrome (MetS) is a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type 2 diabetes and cardiovascular diseases.

Gut microflora and metabolic syndrome

“The recent discovery by our group that patients feeding a fat-enriched diet develop diabetes and obesity through changes of their intestinal microflora has led us to envision innovative strategies aiming to hamper the development of the deleterious intestinal bacterial ecology observed during metabolic diseases,” said Professor Remy Burcelin of INSERM, who led the study.

The current study involved administering the probiotic strain B420 to diabetic mice on a high-fat diet. According to the researchers, the probiotic improved the fasting glycaemia and restored the glucose turnover rate to the level of the control mice fed with normal chow.

“Importantly, the probiotic treatment reduced the fasted insulin levels, but improved the insulin secretion upon glucose challenge, indicating an improved metabolic flexibility and restoration of normal glucose metabolism, and a potential beneficial effect on metabolic syndrome,” said Danisco.

The company added that the beneficial effect of B420 is mediated by a reduction of the pro-inflammatory molecule, plasma lipopolysaccharide (LPS). “B420 changes intestinal mucosal microbiota and reduces the efflux of LPS into plasma, thereby reducing inflammation and improving insulin metabolism,” it said.

Probiotics and obesity

A breakthrough paper published in Nature in December 2006 reported that microbial populations in the gut are different between obese and lean people, and that when the obese people lost weight their microflora reverted back to that observed in a lean person, suggesting that obesity may have a microbial component.

More findings on the topic have since trickled through the scientific web. At a scientific symposium organised by the Beneo Group in April 2008, Dr. Kieran Touhy from the University of Reading noted that obese animals have significantly lower bifidobacteria levels than their lean counterparts, which suggests potential for prebiotic fibres since the growth of these bacteria is selectively promoted by inulin and fructooligosaccharides.

Dr. Nathalie Delzenne from the Catholic University of Louvain in Belgium and Dr. Robert Welch from the University of Ulster presented results from animal and human studies, respectively, which indicated the potential of prebiotic supplementation to regulated food intake.

“This is an interesting new research area which may open up new opportunities for functional foods in the future,” said Dr Julian Stowell, head of scientific affairs for Danisco's Health and Nutrition Platform.

Working overtime puts people at increased risk of coronary heart disease, according to a new study published in the European Heart Journal. CHD occurs when plaque builds up in and narrows the arteries through which blood reaches the heart, which can lead to a heart attack. Specifically, working three to four hours extra (amounting to an 11- or 12-hour work day) was associated with a 1.56-fold increased risk of CHD.

Previous studies have also shown that overtime work is linked to hypertension, sleep problems and depression.

The European researchers followed 6,014 British civil servants aged 39 to 61 for 11 years. Just less than half worked at least one hour of overtime a day, or up to four hours. Those who worked overtime were more often young, male, married or living with a partner, and in more prestigious occupations. The risk of CHD increased in tandem with the number of extra hours worked.

Overtime workers slept less, and reported higher rates of “psychological distress,” according to the study. They often exhibited “Type A behaviour,” which the researchers define as “a chronic, incessant struggle to achieve more and more in less and less time, and is also believed to be characterized by aggressiveness and irritability,” which is also a risk factor for CHD. The researchers also speculate that overtime workers ignore illness, which may aggravate health problems over the long-term.

Perhaps surprisingly, these participants did not exhibit other behaviours that would compromise their heart health: Overtime workers did not drink excessively, smoke or have diabetes. In fact, they actually had better habits—consuming more fruits and vegetables and exercising more often—than those workers who never clocked overtime hours.

In an accompanying editorial entitled “Overtime is bad for the heart,” Gordon McInnes of the University of Glasgow concludes with a quotation from English philosopher Bertrand Russell: “If I were a medical man, I should prescribe a holiday to any patient who considers work important.”

Cutting back on salt use is one of the easiest ways to reduce sodium in your diet, which everyone should consider, even if you are healthy. Why? Because there is no way to tell if your blood pressure is sodium-sensitive so you may – or may not – be prone to developing high blood pressure.